How can I achieve interior silence in order to hear God?

The catechism talks about three expressions of prayer, which are: vocal prayer, meditation, and contemplative prayer. All three are based upon vigilance in dwelling in God's Word and Presence. They help the person to value silence in the middle of a noisy world. 

Vocal prayer is essential. Jesus prayed aloud in the synagogue and (as the Gospels show) he raised his voice in blessing and even in his agony. Even interior prayer must involve the senses. We need to express our feelings externally and have our whole being participate in prayer.

God wants worshippers in Spirit and in Truth, i.e. prayer rising from the soul's depths and expressed by the body. Vocal prayer (being external and so human) is readily accessible to groups. However, even personal prayer needs vocal prayer. We must be aware of him "to whom we speak" (St. Teresa of Jesus). "Vocal prayer can become an initial form of contemplative prayer" (CCC 2703-2704).

Meditation."By meditation the believer seeks to understand so he can respond to the Lord. Attentiveness is often difficult and we can be helped by books (Bible, Gospel, spiritual books, the book of creation, and the today book of history)" (CCC 2705-2706).

As meditation confronts us, we discover the movements in our hearts. We then ask, "Lord, what do you want me to do?"

The Fruits of Meditation. "Christians have a duty to meditate regularly so they will be good soil for God's Word. Meditation mobilizes our inner faculties and deepens our faith to bring about conversion. Believers must meditate on the mysteries of Christ (as in the rosary), and then go further to a union with Jesus" (CCC 2707-2708). 

Contemplative prayer is a "close sharing between friends, taking time frequently to be alone with him whom we know loves us" (St. Teresa of Jesus).

-Response given by Fr. Dominic Feehan, SHM